The adulteration practice in pharmaceutical industries, especially in fats and oils used as a
vehicle in some pharmaceutical products must be identified to assure its quality. In this
study, Fourier Transform Infrared Spectroscopy (FTIR) in combination with
chemometrics techniques of multivariate calibration and discriminant analysis (DA) were
used for the authentication of extra virgin olive oil (EVOO) from rambutan seed fat
(RSF). EVOO, RSF, and the mixture of EVOO-RSF were scanned using FTIR
spectrophotometer at mid-infrared region (4000-650 cm-1
). The results showed that
normal FTIR spectra at wavenumbers region of 1446.8-1409.7 cm-1
and 2368.6-1769.9
cm-1
combined with principle component regression (PCR) offered the best quantitative
model for prediction of RSF levels in EVOO. The coefficient of determination (R2
) values
obtained for the relationship between actual values of RSF and predicted values were of
0.9955 and 0.9915 in calibration and prediction models, respectively. The errors in
calibration and prediction models were relatively low, accounting of 2.17% and 3.68%,
respectively. The classification model between unadulterated or pure EVOO and
adulterated EVOO with RSF was successfully carried out using DA at wavenumbers of
3100-1000 cm-1 without any samples mistakenly classified into the wrong group. FTIR
spectroscopy in combination with chemometrics offered effective tools for authentication
of EVOO against the adulteration practice.
Handheld Near‐Infrared Spectroscopy for Distinction of Extra Virgin Olive Oil from Other Olive Oil Grades Substantiated by Compositional Data
